Kent Green MEP Caroline Lucas has been elected as the party's first leader after a ballot of several thousand party members.

The party has never had a single leader before and Dr Lucas won the post against her only rival, Ashley Gunstock.

The result represents a major shift in the organisation of the party.

Dr Lucas has become one of the Green's best-known figures and has been an MEP for the south east region since 1999. She sits on the Parliament's Trade, Environment and Climate Change Committees and is vice president of the Animal Welfare Intergroup.

She has said that a priority for the party would be to start taking control of local councils and doing better in general elections.

In a campaign message, she said: "The election of a leadership team offers us new and exciting opportunities to take the radical message of Green politics into the mainstream, where it belongs.

"The need for Green political influence has never been so urgent, and never has there been so much at stake. I would regard it as a major part of my role to communicate that even more effectively."

The party has previously resisted the idea of a single leader but that changed last year when members voted in favour of creating the post.

Lucas will only be allowed to serve a maximum of 10 years under party rules. If the leader is a woman, the rules say that the deputy leader's post must go to a man.